Explanation:

• Peneplain is a lowland of faint relief with some low resistant remnants called monadnocks formed due to running water erosion: This statement is correct. A peneplain is a nearly level surface of low relief that is underlain by nearly horizontal strata. Monadnocks are resistant rock outcrops that stand above the general level of the peneplain.
• Pediplain found at the foot of glacial mountains are covered with glacio-fluvial deposits: This statement is incorrect. Pediplains are low-relief erosional surfaces, but they are typically associated with arid regions rather than glacial mountains. Glacio-fluvial deposits are more commonly found in areas influenced by glacial processes, not in pediplains.
• Outwash plain is an erosional plain formed due to torrential rain in arid regions: This statement is incorrect. Outwash plains are typically associated with glacial environments, not arid regions. They are formed by the deposition of sediment carried by meltwater streams from a glacier.